SLIDE 1
TAAT 2012 1
TAAT 2012 2
OUTLINE
- Historical view of contact cleaning
- Current market Drivers
- Science of adhesion
- Surface roughness analysis
- Adhesion measurements
- Other results
- Conclusions
COATED PRODUCTS IN OPTICAL APPLICATIONS Sheila Hamilton Teknek Ltd - - PowerPoint PPT Presentation
COATED PRODUCTS IN OPTICAL APPLICATIONS Sheila Hamilton Teknek Ltd - - PowerPoint PPT Presentation
CONTACT CLEANING FOR COATED PRODUCTS IN OPTICAL APPLICATIONS Sheila Hamilton Teknek Ltd TAAT 2012 1 OUTLINE Historical view of contact cleaning Current market Drivers Science of adhesion Surface roughness analysis Adhesion
SLIDE 2
SLIDE 3
TAAT 2012 3
CLEANING FUNDAMENTALS
- Adhesive force between the elastomer
roller and the particle must be greater than the force between the particle and the substrate
- The adhesive force between the particle
and the adhesive must be greater than that between the elastomer roller and the particle
SLIDE 4
TAAT 2012 4
HISTORICAL VIEW
- Softer rollers have greater contact area
- Softer rollers clean better
- Soft rollers deform around particles
- Glossy rollers are smooth
- Smooth rollers clean better
SLIDE 5
TAAT 2012 5
MARKET DRIVERS
- Thinner films
- Increased processing of sheets
- Specialist functional coatings
- Structured films eg prism films
- Static generative materials
- Unbalanced surfaces
SLIDE 6
TAAT 2012 6
SHORE HARDNESS
10 20 30 40 50 60 70 80 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Holding capacity Shore
SLIDE 7
TAAT 2012 7
INTERFACIAL FORCES
SLIDE 8
TAAT 2012 8
EXAMPLES OF ADHESION FORCES
SLIDE 9
TAAT 2012 9
MACRO ADHESION
RUBBER COPPER STEEL Cu/KAPTON POLYESTER POLYCARBONATE (Gloss) (Matt) SOFT
1.17 3.26 0.51 2.55 2.37
PANEL
1.49 3.32 0.81 2.63 1.07
FILM
0.63 0.81 0.34 1.68 1.4
F3
0.11 0.11 0.11 0.05 0.12
NANO
0.08 0.04 0.07 0.75 0.34
SLIDE 10
TAAT 2012 10
CONTACT AREA
Contact area is impacted by
- Roller surface roughness
- Pressure
- Shore hardness
- Particle morphology
SLIDE 11
TAAT 2012 11
SURFACE ROUGHNESS
Scan Size Sample name 1 2 3 Soft 2.169 11.143 38.582 Panel 7.355 13.493 23.467 Nanoclean 3.616 1.400 6.292 Film 7.453 16.861 18.54 F3 31.009 49.085 98.334
SLIDE 12
TAAT 2012 12
SURFACE OF SOFT ELASTOMER
SLIDE 13
TAAT 2012 13
SURFACE OF PANEL ELASTOMER
SLIDE 14
TAAT 2012 14
SURFACE OF F3 ELASTOMER
SLIDE 15
TAAT 2012 15
SURFACE OF NANOCLEEN ELASTOMER
SLIDE 16
TAAT 2012 16
SURFACE ROUGHNESS
SLIDE 17
TAAT 2012 17
SUMMARY
- For small particles surface roughness has
to be considered on a microscopic scale
- Ideally surface asperities should be
matched to the size of the particle of contamination
- The flexibility of the roughness peaks is
important.
SLIDE 18
TAAT 2012 18
FORCE DISPLACEMENT CURVES
- Gold
SLIDE 19
TAAT 2012 19
FORCE DISPLACEMENT CURVES
- Polystyrene
SLIDE 20
TAAT 2012 20
FORCE DISPLACEMENT CURVES
- Silica
SLIDE 21
TAAT 2012 21
ADHESION FORCES
Type of Probe Sample name Silica Gold-coated silica Polystyrene Soft 752.08±147.06 951.87±69.48 1027.79±109.82 Panel 848.11±112.98 823.55±160.72 847.12±214.75 Nanoclean 803.08±443.79 285.14±161.34 1073.17±629.94 Film 866.80±144.75 1152.12±125.74 1177.89±81.77 F3 1076.98±420.92 746.64±329.49 813.09±393.31
SLIDE 22
TAAT 2012 22
ADHESION FORCES
- Panel and soft and film
SLIDE 23
TAAT 2012 23
ADHESION FORCES
- F3 and Nanocleen
SLIDE 24
TAAT 2012 24
SUMMARY
- Hydrophobicity of materials is important for
adhesion
- Adhesion on the macro scale does not
relate to the micro scale
- Surface roughness on a micro scale
causes variations in the adhesion forces
SLIDE 25
TAAT 2012 25
CONCLUSIONS
- Moisture affects cleaning performance
- Good cleaning improves wettability
- Lot more experimentation required
SLIDE 26
TAAT 2012 26
ACKNOWLEDGEMENTS
- Dr Zhenyu (Jason) Zhang and